IBM and University of Georgia have recently submitted a notes to W3C for the description of the semantics of a Web service. The title of the note, "Web Service Semantics - WSDL-S", is somewhat misleading, but the idea proposed really worths some attention.

That's pretty much all you can tell using native WSDL. The consumer of the PO services now knows it need to send a message to you as *syntactically* defined by the GED "tns:processPurchaseOrderRequest", and it will get something back as defined by GED "processPurchaseOrderResponse".

<!Category is added as an extensible element of an interface> <!Precondition and effect are added as extensible elements on an operation>There is indeed one glitch, but it's easily fixable and I won't worry about it: the proposal is based on an old version of WSDL2.0. It needs to be updated to reflect the latest WSDL 2.0 draft. . It's worth pointing out that it also supports WSDL1.1.

Related standard initiatives

The proposals for creating two new W3C working groups are being circulated in W3C membership. One for Web services semantics characterization which is to define requirements and scenarios, and the other to standardize WSDL-S.

Don't confuse WSDL-S with some other initiatives

OWL-S. It provides a language for actually defining the semantics of a services. WSDL-S may point to an instance of OWL-S